81522128 has 10 divisors (see below), whose sum is σ = 157949154. Its totient is φ = 40761056.

The previous prime is 81522127. The next prime is 81522139. The reversal of 81522128 is 82122518.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 77228944 + 4293184 = 8788^2 + 2072^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81522128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81522127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2547551 + ... + 2547582.

Almost surely, 2^81522128 is an apocalyptic number.

It is an amenable number.

81522128 is a deficient number, since it is larger than the sum of its proper divisors (76427026).

81522128 is a wasteful number, since it uses less digits than its factorization.

81522128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5095141 (or 5095135 counting only the distinct ones).

The product of its digits is 2560, while the sum is 29.

The square root of 81522128 is about 9028.9605160284. The cubic root of 81522128 is about 433.6025582743.

The spelling of 81522128 in words is "eighty-one million, five hundred twenty-two thousand, one hundred twenty-eight".